Yamaha 25hp 2-Stroke 1980's fuel issue

[duck hunter1]

When motor starts after having sat, it runs until the fuel bowl is empty. won't allow any more fuel to enter fuel bowl. After opening bowl screw on bottom and tapping on carb, lift up and drop the motor, pour fuel in carb, I can finally get the fuel to flow to the bowl. (There is no obstruction in the fuel line, have installed a new fuel line, have removed and cleaned/checked carb and float and all appears to be fine). Once it starts again, it runs fine all day without a problem until the next time I take the boat out). What else should I be looking for to solve the problem?

 

[Yamajoe]

Re: Yamaha 25hp 2-Stroke 1980's fuel issue

You need to replace your float valve needles, they are sticky. Inside the body of your carb is a float, when fuel level drops the float drops allowing more fuel to top the chamber up, float rises and stops the entry of more fuel into the bowl. A sticky needle valve (rubber tipped) prevents fuel from entering the bowl; the other problem we have with these valves is when the tips are damaged/frayed it does not shut off the entry of fuel, this situation leads to fuel overflowing from the side of carbs.

 

[duck hunter1]

Re: Yamaha 25hp 2-Stroke 1980's fuel issue

Thanks for the info; will try that next and thank you for your service to our Country.